From: "Darrick J. Wong" <djwong@us.ibm.com>
To: Andreas Dilger <adilger.kernel@dilger.ca>,
Theodore Tso <tytso@mit.edu>,
"Darrick J. Wong" <djwong@us.ibm.com>
Cc: Sunil Mushran <sunil.mushran@oracle.com>,
Martin K Petersen <martin.petersen@oracle.com>,
Greg Freemyer <greg.freemyer@gmail.com>,
Amir Goldstein <amir73il@gmail.com>,
linux-kernel <linux-kernel@vger.kernel.org>,
Andi Kleen <andi@firstfloor.org>, Mingming Cao <cmm@us.ibm.com>,
Joel Becker <jlbec@evilplan.org>,
linux-fsdevel <linux-fsdevel@vger.kernel.org>,
linux-ext4@vger.kernel.org, Coly Li <colyli@gmail.com>
Subject: [PATCH 17/28] ext4: Calculate and verify checksums for htree nodes
Date: Sat, 08 Oct 2011 00:55:36 -0700 [thread overview]
Message-ID: <20111008075536.20506.13681.stgit@elm3c44.beaverton.ibm.com> (raw)
In-Reply-To: <20111008075343.20506.23155.stgit@elm3c44.beaverton.ibm.com>
Calculate and verify the checksum for directory index tree (htree) node blocks.
The checksum is stored in the last 4 bytes of the htree block and requires the
dx_entry array to stop 1 dx_entry short of the end of the block.
Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
---
fs/ext4/namei.c | 164 ++++++++++++++++++++++++++++++++++++++++++++++++++++++-
1 files changed, 160 insertions(+), 4 deletions(-)
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index d0158f2..daa0c18 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -145,6 +145,15 @@ struct dx_map_entry
u16 size;
};
+/*
+ * This goes at the end of each htree block. If you want to use the
+ * reserved field, you'll have to update the checksum code to include it.
+ */
+struct dx_tail {
+ u32 reserved;
+ u32 checksum; /* crc32c(uuid+inum+dirblock) */
+};
+
static inline ext4_lblk_t dx_get_block(struct dx_entry *entry);
static void dx_set_block(struct dx_entry *entry, ext4_lblk_t value);
static inline unsigned dx_get_hash(struct dx_entry *entry);
@@ -180,6 +189,116 @@ static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
struct inode *inode);
+/* checksumming functions */
+static struct dx_countlimit *get_dx_countlimit(struct inode *inode,
+ struct ext4_dir_entry *dirent,
+ int *offset)
+{
+ struct ext4_dir_entry *dp;
+ struct dx_root_info *root;
+ int count_offset;
+
+ if (le16_to_cpu(dirent->rec_len) == EXT4_BLOCK_SIZE(inode->i_sb))
+ count_offset = 8;
+ else if (le16_to_cpu(dirent->rec_len) == 12) {
+ dp = (struct ext4_dir_entry *)(((void *)dirent) + 12);
+ if (le16_to_cpu(dp->rec_len) !=
+ EXT4_BLOCK_SIZE(inode->i_sb) - 12)
+ return NULL;
+ root = (struct dx_root_info *)(((void *)dp + 12));
+ if (root->reserved_zero ||
+ root->info_length != sizeof(struct dx_root_info))
+ return NULL;
+ count_offset = 32;
+ } else
+ return NULL;
+
+ if (offset)
+ *offset = count_offset;
+ return (struct dx_countlimit *)(((void *)dirent) + count_offset);
+}
+
+static __le32 ext4_dx_csum(struct inode *inode, struct ext4_dir_entry *dirent,
+ int count_offset, int count)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+ struct ext4_inode_info *ei = EXT4_I(inode);
+ __u32 crc;
+ int size;
+
+ size = count_offset + (count * sizeof(struct dx_entry));
+
+ crc = ext4_chksum(sbi, ei->i_uuid_inum_crc, (__u8 *)dirent, size);
+ return cpu_to_le32(crc);
+}
+
+static int ext4_dx_csum_verify(struct inode *inode,
+ struct ext4_dir_entry *dirent)
+{
+ struct dx_countlimit *c;
+ struct dx_tail *t;
+ int count_offset, limit, count;
+
+ if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
+ EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+ return 1;
+
+ c = get_dx_countlimit(inode, dirent, &count_offset);
+ if (!c) {
+ EXT4_ERROR_INODE(inode, "dir seems corrupt? Run e2fsck -D.");
+ return 1;
+ }
+ limit = le16_to_cpu(c->limit);
+ count = le16_to_cpu(c->count);
+ if (count_offset + (limit * sizeof(struct dx_entry)) >
+ EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
+ EXT4_ERROR_INODE(inode, "metadata_csum set but no space for "
+ "tree checksum found. Run e2fsck -D.");
+ return 1;
+ }
+ t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
+
+ if (t->checksum != ext4_dx_csum(inode, dirent, count_offset, count))
+ return 0;
+ return 1;
+}
+
+static void ext4_dx_csum_set(struct inode *inode, struct ext4_dir_entry *dirent)
+{
+ struct dx_countlimit *c;
+ struct dx_tail *t;
+ int count_offset, limit, count;
+
+ if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
+ EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+ return;
+
+ c = get_dx_countlimit(inode, dirent, &count_offset);
+ if (!c) {
+ EXT4_ERROR_INODE(inode, "dir seems corrupt? Run e2fsck -D.");
+ return;
+ }
+ limit = le16_to_cpu(c->limit);
+ count = le16_to_cpu(c->count);
+ if (count_offset + (limit * sizeof(struct dx_entry)) >
+ EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
+ EXT4_ERROR_INODE(inode, "metadata_csum set but no space for "
+ "tree checksum. Run e2fsck -D.");
+ return;
+ }
+ t = (struct dx_tail *)(((struct dx_entry *)c) + limit);
+
+ t->checksum = ext4_dx_csum(inode, dirent, count_offset, count);
+}
+
+static inline int ext4_handle_dirty_dx_node(handle_t *handle,
+ struct inode *inode,
+ struct buffer_head *bh)
+{
+ ext4_dx_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
+ return ext4_handle_dirty_metadata(handle, inode, bh);
+}
+
/*
* p is at least 6 bytes before the end of page
*/
@@ -239,12 +358,20 @@ static inline unsigned dx_root_limit(struct inode *dir, unsigned infosize)
{
unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(1) -
EXT4_DIR_REC_LEN(2) - infosize;
+
+ if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
+ EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+ entry_space -= sizeof(struct dx_tail);
return entry_space / sizeof(struct dx_entry);
}
static inline unsigned dx_node_limit(struct inode *dir)
{
unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(0);
+
+ if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
+ EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+ entry_space -= sizeof(struct dx_tail);
return entry_space / sizeof(struct dx_entry);
}
@@ -390,6 +517,15 @@ dx_probe(const struct qstr *d_name, struct inode *dir,
goto fail;
}
+ if (!buffer_verified(bh) &&
+ !ext4_dx_csum_verify(dir, (struct ext4_dir_entry *)bh->b_data)) {
+ ext4_warning(dir->i_sb, "Root failed checksum");
+ brelse(bh);
+ *err = ERR_BAD_DX_DIR;
+ goto fail;
+ }
+ set_buffer_verified(bh);
+
entries = (struct dx_entry *) (((char *)&root->info) +
root->info.info_length);
@@ -450,6 +586,17 @@ dx_probe(const struct qstr *d_name, struct inode *dir,
if (!(bh = ext4_bread (NULL,dir, dx_get_block(at), 0, err)))
goto fail2;
at = entries = ((struct dx_node *) bh->b_data)->entries;
+
+ if (!buffer_verified(bh) &&
+ !ext4_dx_csum_verify(dir,
+ (struct ext4_dir_entry *)bh->b_data)) {
+ ext4_warning(dir->i_sb, "Node failed checksum");
+ brelse(bh);
+ *err = ERR_BAD_DX_DIR;
+ goto fail;
+ }
+ set_buffer_verified(bh);
+
if (dx_get_limit(entries) != dx_node_limit (dir)) {
ext4_warning(dir->i_sb,
"dx entry: limit != node limit");
@@ -549,6 +696,15 @@ static int ext4_htree_next_block(struct inode *dir, __u32 hash,
if (!(bh = ext4_bread(NULL, dir, dx_get_block(p->at),
0, &err)))
return err; /* Failure */
+
+ if (!buffer_verified(bh) &&
+ !ext4_dx_csum_verify(dir,
+ (struct ext4_dir_entry *)bh->b_data)) {
+ ext4_warning(dir->i_sb, "Node failed checksum");
+ return -EIO;
+ }
+ set_buffer_verified(bh);
+
p++;
brelse(p->bh);
p->bh = bh;
@@ -1224,7 +1380,7 @@ static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
err = ext4_handle_dirty_metadata(handle, dir, bh2);
if (err)
goto journal_error;
- err = ext4_handle_dirty_metadata(handle, dir, frame->bh);
+ err = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
if (err)
goto journal_error;
brelse(bh2);
@@ -1411,7 +1567,7 @@ static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
frame->bh = bh;
bh = bh2;
- ext4_handle_dirty_metadata(handle, dir, frame->bh);
+ ext4_handle_dirty_dx_node(handle, dir, frame->bh);
ext4_handle_dirty_metadata(handle, dir, bh);
de = do_split(handle,dir, &bh, frame, &hinfo, &retval);
@@ -1586,7 +1742,7 @@ static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
dxtrace(dx_show_index("node", frames[1].entries));
dxtrace(dx_show_index("node",
((struct dx_node *) bh2->b_data)->entries));
- err = ext4_handle_dirty_metadata(handle, dir, bh2);
+ err = ext4_handle_dirty_dx_node(handle, dir, bh2);
if (err)
goto journal_error;
brelse (bh2);
@@ -1612,7 +1768,7 @@ static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
if (err)
goto journal_error;
}
- err = ext4_handle_dirty_metadata(handle, dir, frames[0].bh);
+ err = ext4_handle_dirty_dx_node(handle, dir, frames[0].bh);
if (err) {
ext4_std_error(inode->i_sb, err);
goto cleanup;
next prev parent reply other threads:[~2011-10-08 7:55 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-10-08 7:53 [PATCH v2 00/28] ext4: Add metadata checksumming Darrick J. Wong
2011-10-08 7:53 ` [PATCH 01/28] ext4: ext4_dx_add_entry should dirty directory metadata with the directory inode Darrick J. Wong
2011-10-08 7:53 ` [PATCH 02/28] ext4: ext4_rename should dirty dir_bh with the correct directory Darrick J. Wong
2011-10-08 7:54 ` [PATCH 03/28] ext4: ext4_mkdir should dirty dir_block with the parent inode Darrick J. Wong
2011-10-08 7:54 ` [PATCH 04/28] ext4: Prevent stack overrun in ext4_file_open when recording last known mountpoint Darrick J. Wong
2011-10-08 7:54 ` [PATCH 05/28] ext4: Fix endian problem in MMP initialization Darrick J. Wong
2011-10-08 7:54 ` [PATCH 06/28] ext4: Create a new BH_Verified flag to avoid unnecessary metadata validation Darrick J. Wong
2011-10-08 7:54 ` [PATCH 07/28] ext4: Create a rocompat flag for extended metadata checksumming Darrick J. Wong
2011-10-08 7:54 ` [PATCH 08/28] ext4: Record the checksum algorithm in use in the superblock Darrick J. Wong
2011-10-08 7:54 ` [PATCH 09/28] ext4: Only call out to crc32c if necessary Darrick J. Wong
2011-10-08 7:54 ` [PATCH 10/28] ext4: Calculate and verify superblock checksum Darrick J. Wong
2011-10-08 7:54 ` [PATCH 11/28] ext4: Calculate and verify inode checksums Darrick J. Wong
2011-10-12 19:45 ` Andreas Dilger
2011-10-12 21:03 ` Darrick J. Wong
2011-10-13 0:02 ` Andreas Dilger
2011-10-08 7:55 ` [PATCH 12/28] ext4: Use i_generation in inode-related metadata checksums Darrick J. Wong
2011-10-12 19:52 ` Andreas Dilger
2011-10-12 21:28 ` Darrick J. Wong
2011-10-13 0:06 ` Andreas Dilger
2011-10-08 7:55 ` [PATCH 13/28] ext4: Create bitmap checksum helper functions Darrick J. Wong
2011-10-08 7:55 ` [PATCH 14/28] ext4: Calculate and verify checksums for inode bitmaps Darrick J. Wong
2011-10-08 7:55 ` [PATCH 15/28] ext4: Calculate and verify block bitmap checksum Darrick J. Wong
[not found] ` <AE869D1A-2A06-4849-8752-74924B0C05BD@dilger.ca>
2011-10-13 7:16 ` Darrick J. Wong
2011-11-07 20:00 ` Darrick J. Wong
2011-11-07 21:44 ` Andreas Dilger
2011-11-10 0:57 ` Darrick J. Wong
2011-11-10 2:34 ` Andreas Dilger
2011-10-08 7:55 ` [PATCH 16/28] ext4: Verify and calculate checksums for extent tree blocks Darrick J. Wong
2011-10-08 7:55 ` Darrick J. Wong [this message]
[not found] ` <F6453844-06CC-4245-BB39-EBA4327D4C92@dilger.ca>
2011-10-13 7:21 ` [PATCH 17/28] ext4: Calculate and verify checksums for htree nodes Darrick J. Wong
2011-10-08 7:55 ` [PATCH 18/28] ext4: Calculate and verify checksums of directory leaf blocks Darrick J. Wong
2011-10-08 7:55 ` [PATCH 19/28] ext4: Calculate and verify checksums of extended attribute blocks Darrick J. Wong
2011-10-08 7:55 ` [PATCH 20/28] ext4: Add new feature to make block group checksums use metadata_csum algorithm Darrick J. Wong
2011-10-08 7:56 ` [PATCH 21/28] ext4: Add checksums to the MMP block Darrick J. Wong
2011-10-08 7:56 ` [PATCH 22/28] jbd2: Update structure definitions and flags to support extended checksumming Darrick J. Wong
2011-10-08 7:56 ` [PATCH 23/28] jbd2: Grab a reference to the crc32c driver only when necessary Darrick J. Wong
2011-10-08 7:56 ` [PATCH 24/28] jbd2: Update structure definitions and flags to support extended checksumming Darrick J. Wong
2011-10-08 7:56 ` [PATCH 25/28] jbd2: Checksum revocation blocks Darrick J. Wong
2011-10-08 7:56 ` [PATCH 26/28] jbd2: Checksum descriptor blocks Darrick J. Wong
2011-10-08 7:56 ` [PATCH 27/28] jbd2: Checksum commit blocks Darrick J. Wong
2011-10-08 7:56 ` [PATCH 28/28] jbd2: Checksum data blocks that are stored in the journal Darrick J. Wong
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